髋臼翻转造盖术治疗成人髋臼发育不良的生物力学研究

目的探讨髋臼翻转造盖术治疗成人髋臼发育不良的力学机理。方法收集适宜行髋臼翻转造盖术的成人髋臼发育不良12例的术前术后X线片,建立有限元网格,分析其力学变化并与正常髋关节进行对照研究。结果术后与术前各部位受力明显改变具有显著性差异(P<0·01),其中术前髋臼应力集中于外上缘,术后髋臼应力分布于臼顶,应力分散,与正常髋臼受力接近。结论髋臼翻转造盖术可明显改善髋臼局部受力情况,使成人髋臼发育不良术后髋关节受力趋于正常。     

3D-CT初步分析发育性髋臼发育不良患儿髋臼前倾的原因

[目的]观察发育性髋臼发育不良患儿病变髋是否存在髋臼过度前倾,并分析髋臼前倾的原因.[方法]回顾性收集50例单髋脱位患儿和30例正常对照组髋关节的3D-CT影像学资料.病例组:男11例,女39例;年龄6～ 60个月,平均18个月.左侧髋脱位29例,右侧髋脱位21例.对照组:男16例,女14例;年龄7～48个月,平均20个月.所有实验对象均测量髋臼前倾角(AA)、坐骨旋转角(IA)、耻骨旋转角(PA)、耻骨相对长度(PRL)和坐骨相对距离(IRD),统计学分析对比病例组和对照组上述指标是否存在统计学差异.[结果]正常对照组左侧髋和右侧髋的AA、IA、PA、PRL和IRD差别均无统计学意义(P＞0.05).单髋脱位患儿脱位侧髋和未受累侧髋的PA差别无统计学意义(P＞0.05).脱位侧髋的PRL值小于未受累侧髋,差异有统计学意义(P＜0.05).脱位侧髋的AA、IA和IRD均大于未受累侧髋,差异有统计学意义(P＜0.05).无论是在脱位侧髋还在未受累侧髋,IA均与AA和IRD呈正相关.[结论]发育性髋臼发育不良患儿髋臼过度前倾是普遍存在的,除了髋臼前壁缺陷外,患儿脱位侧髋的坐骨外侧旋转引起坐骨外侧移位也是髋臼发生过度前倾的原因之一.     

股骨及髋臼纵向撞击伤的计算机模拟生物力学研究

目的建立具有生物力学特性的股骨及大部分骨盆三维有限元模型,探讨股骨远端发生撞击时响应过程及股骨各部和髋臼损伤的生物力学基础。方法采用GE多层螺旋CT对1例健康志愿者进行从骨盆上缘到胫骨平台部的CT扫描,三维影像重建,数据转换,运用自编程序与vtk软件相结合的方法,模仿刚体撞击股骨远端。分析在撞击时股骨干、股骨转子部、股骨颈和髋臼等部位的应力改变。结果当着力点位于股骨远端时,应力沿股骨干、股骨转子部、股骨颈向髋臼传导,并产生不同强度。前三部位应力达到峰值时间接近,髋臼应力发生延迟。结论股骨及髋臼纵向撞击伤的三维有限元模型可研究现实中难以反复再现的撞击状态;撞击中骨横截面积的变化和应力传导方向的改变会产生应力集中和梯度差,这可能是撞击伤的生物力学机制之一。     

髋臼发育不良髋臼缘生物力学测定

[目的]证实由于兔髋臼发育不良，股骨头被髋臼所覆盖的面积减少，股骨头的球状关节和髋臼的舟状关节负重面趋于集中，头臼关节不能耐受高度集中的强大的机械应力作用，最终导致髋关节脱位．[方法]本实验利用七V13型数据采集记录仪、X线片和组织病理切片对对照组和实验组髋关节进行力学测定和病理学观察一[结果]实验组髋臼缘软骨逐渐发生退变和变形，髋臼缘A、B、C、D4点位置，所受应力均有变化。对照组和实验组，t检验，P〈0．01。[结论]本实验对髋臼发育不良兔髋臼缘力学测定，可以推测人类先天性髋关节脱位的机理和原冈与髋臼发育不良有密切联系。先天性髋关节脱位患儿应早期发现，早期治疗，提高临床治疗效果。     

髋臼发育不良的光弹性生物力学研究

目的 从生物力学角度探讨髋臼发育不良继发骨关节炎的发病机理,为髋臼旋转截骨术提供依据。方法 用环氧树脂制作骨盆、股骨模型,其中包括４个不同Ｓｈａｒｐ角、３个不同软骨厚度及３个颈干角模型,采用二维光弹性方法进行生物力学分析。结果 随着Ｓｈａｒｐ角的增大,髋关节的合力增大,生物应力向髋臼外侧缘移动;关节软骨缺损一半时,髋关节合力未见明显变化,当关节软骨不存在时,生物应力为正常时的２．５倍;随着颈干角的增大,生物应力集中的位置没有变化,但生物应力及合力随之增大。结论 髋臼发育不良因生物力学因素可继发骨关节炎,髋臼旋转截骨术是对其有效的治疗方法。     

髋臼横断骨折前路及后路钢板内固定的生物力学研究

目的　比较髋臼横断骨折前柱单钢板内固定及后柱单钢板内固定的稳定性。方法　取成年男性防腐骨盆标本 4个 ,制成半骨盆标本 8个 ,模拟髋臼横断骨折 ,将 8个半骨盆标本随机分为二组 ,分别给予①前柱单钢板 ;②后柱单钢板内固定。通过股骨头对髋臼进行连续垂直加载 ,直至内固定失败。结果　髋臼横断骨折前柱单钢板内固定及后柱单钢板内固定能承受的最大负载分别为 489± 71.33N、 2 5 2 .2 5± 92 12N。结论　前柱单钢板内固定的稳定性高于后柱单钢板内固定     

髋臼横断骨折不同内固定方法的生物力学研究及临床意义

目的对髋臼横断骨折六种常用的内固定方法进行生物力学比较。方法取成年男性防腐半骨盆标本60个,模拟髋臼横断骨折。将标本随机分为六组,分别按下列方法内固定:A.前柱单钢板;B.后柱单钢板;C.后柱双钢板;D.前柱单钢板加后柱单钢板;E.前柱拉力螺钉加后柱单钢板;F.前柱拉力螺钉加后柱拉力螺钉。本实验采用生物力学试验机,将传动杆与股骨颈截面牢固连接,将股骨头放入髋臼进行垂直加载,记录下内固定失败时各标本的相应负载,采用Stata4.0统计学软件进行方差分析、Scheffe法检验。结果对于髋臼横断骨折,A组、B组、C组、D组、E组及F组能承担的最大负载分别为:(520.02±68.46)N,(308.04±79.32)N,(837.99±109.68)N,(1024.93±108.77)N,(1022.40±127.67)N及(1121.19±127.17)N,经Scheffe法两两比较,在采用单柱内固定的A、B、C三组数据中具有显著性差异:C组>A组>B组(P<0.05),在采用双柱内固定的D、E、F三组数据无显著性差异(P>0.05)。采用双柱内固定的D、E、F三组数据均大于采用单柱内固定的A、B、C三组。结论双柱内固定的稳定性高于单柱内固定。在行单柱内固定方法中:后柱双钢板内固定的稳定性高于前柱单钢板内固定,前柱单钢板内固定的稳定性高于后柱单钢板内固定。在双柱内固定的方法中无统计学区别。     

成人髋臼发育不良生物力学改变及治疗现状

成人髋臼发育不良是指髋臼与股骨头之间失去正常匹配关系 ,导致髋关节生物力学破坏 ,是成年人继发性骨关节炎的主要病因之一。1　影像学变化在普通X线平片上衡量髋臼发育不良的参数很多 ,其中最常用AI与CE角 ,AI值 >3 0°及 (或 )CE角 <2 0°既可诊断为髋臼发育不良。无论是AI值增大 ,还是CE角减小 ,都是以髋臼变浅及髋臼对股骨头包容不良等变化为基础的。以上各种参数只能用来衡量髋臼深浅或上外侧的发育情况。Murphy等对 2 0例患髋及 49例正常髋臼进行CT和MR三维扫描发现正常髋臼是完美的半球形 ,向前倾 2 0° ,外翻 5 3°。发育…     

复杂髋臼骨折内固定的生物力学研究

目的分析研究复杂髋臼骨折内固定的生物学特点,为临床治疗提供相关生物力学依据。方法以髋臼横形骨折及后壁骨折为骨折模型,采用3种不同内固定方式[前柱钢板加后柱螺钉（SPG）、前柱螺钉加后柱钢板（PSG）、双柱钢板（PPG）]进行生物力学实验。结果3种不同内固定方式下的各点应变值与正常状态下应变值之比,分别记做SPG/NG（1组）、PPG/NG（2组）、PSG/NG（3组）,每组根据要求设立5个应变点。1组为：2.70、1.47、2.18、1.59、1.67;2组为：0.94、0.89、0.75、0.76、0.92;3组为1.06、1.05、1.32、1.52、1.22。3组经方差齐性检验和t检验比较,差异均有统计学意义（P〈0.05）。结论前柱螺钉加后柱钢板组的效果不如双柱钢板组及前柱钢板加后柱螺钉组,前柱钢板加后柱螺钉组略优于双柱钢板组。     

Effect of Pelvic Osteotomy in the Skeletally Immature on Acetabular Coverage

Background

Although pelvic osteotomy in children has been effective in re-establishing containment of the hip joint, its impact on hip joint development with respect to acetabular coverage is ill defined.

Purpose

The purpose of this study is to determine the prevalence of acetabular overcoverage in patients who had pelvic osteotomy during childhood and its impact on patient function.

Patients and Methods

Between 1980 and 2008, all patients who had a pelvic osteotomy done at our institution for non-neuropathic hip dysplasia (DDH) or secondary to Legg–Calvé–Perthes disease (LCP) prior to skeletal maturity were reviewed. A clinical assessment and the WOMAC, UCLA Activity Score, Marx activity score, and SF-36 quality-of-life questionnaires were completed. A standardized AP pelvic X-ray was performed to determine the acetabular coverage, signs of retroversion, and degenerative changes.

Results

Twenty-eight patients (32 hips) were identified, of which 14 (9 DDH, 5 LCP) agreed to participate. Impingement sign was positive in eight patients (six DDH, two LCP). Crossover and ischial spine signs were each present in ten hips. Tonnis grades were: 0 in 1 hip, 1 in 10 hips, 2 in 2 hips, and 3 in 1 hip. The mean Tonnis angle was 11.6 ± 8.6°. The mean CE angle was 24.0 ± 15.9° with six hips having a CE angle <20° and one hip with a CE angle >40°. There was no correlation between crossover sign or ischial sign and Tonnis grade (p = 0.739), hip pain (p = 0.520), or impingement sign (p = 1.00).

Conclusions

Acetabular overcoverage is common in patients who underwent pelvic osteotomy during childhood. No correlation was identified between retroversion and hip pain in our patient cohort.     

髋臼假体前倾角影像评估

目的：探讨一种简便又相对准确的计算前倾角的方法。方法：从髋前后位X线片测量并通过数学公式进行计算，且对这一数学公式进行试验性测量计算和研究。结果：公式计算的角度与实际值基本相近，证明这一数学公式的临床可用性。结论：对过去的一些测量方法进行总结对比，新方法有一定的优越性。     

髋臼横断骨折两种内固定方式的生物力学研究

目的　对髋臼横断骨折两种常用的内固定方法进行生物力学比较。方法　取成年男性防腐骨盆标本 4个 ,制成半骨盆标本 8个 ,模拟髋臼横断骨折 ,随机分为二组 ,给予后柱单钢板及后柱双钢板内固定。通过传动杆与股骨头对髋臼进行连续垂直加载 ,直至内固定失败。结果　髋臼横断骨折后柱单钢板内固定及后柱双钢板内固定能承受的最大负载分别为 2 5 2 2 5±92 12N及 10 40± 143 0 6N。结论　后柱双钢板内固定的稳定性高于后柱单钢板内固定     

Cup Anteversion in Hip Resurfacing: Validation of EBRA and the Presentation of a Simple Clinical Grading System

The use of large metal on metal bearings has led to a reduction in the risk of dislocation post hip arthroplasty. Because of this, and also because of the technical difficulties associated with resurfacing surgery in particular, it could be argued that a less meticulous approach to acetabular cup placement has developed in comparison with conventional metal on polyethylene arthroplasty. Resurfacing cups may produce significant clinical problems when placed at the extremes of version, including increased production of metal debris and psoas tendonitis. Presented in this article is evidence that EBRA software (Einzel-Bild-Roentgen-Analysis, University of Innsbruck, Austria) can be used to reliably assess the version of resurfacing cups, when radiographs are of sufficient quality. The cups have characteristic appearances when placed at the extremes of version. These characteristics can allow the surgeon to identify poorly positioned cups without the use of software.     

Gender and Racial Differences in Focal and Global Acetabular Version

The purpose of this study was to compare the acetabular version between male and female pelvises. We hypothesized that female acetabula would demonstrate more retroversion because Pincer-type femoroacetabular impingement (FAI) is associated with acetabular retroversion, which is more commonly observed in females. 120 bony pelvic specimens were randomly collected. The version was measured at three different axial sections of each acetabulum: cranial, central, and caudal. Males demonstrated significantly less anteversion than females in every section. The global version (the average of all three measurements) was also significantly different between males and females (16° ± 7° and 19° ± 8° respectively, P < 0.001). Of the 240 examined acetabuli, 21 demonstrated cranial retroversion (16 males & 5 females). The data showed no significant difference (P = 0.353) between global version of African Americans (18° ± 9°) and Caucasians (17° ± 7°). The results of this study suggest that symptomatic FAI in the female population likely reflects a complex interplay of femoral and acetabular dysmorphology and cannot be explained by differences in acetabular version alone.     

Acetabular Retroversion Is a Risk Factor for Less Optimal Outcome After Femoroacetabular Impingement Surgery

BackgroundPatients with acetabular retroversion are at risk of labral tear and hip pain. It is unknown whether femoroacetabular osteoplasty (FAO) without reverse periacetabular osteotomy can be used in these patients. This study evaluated the outcome of mini-open FAO in patients with acetabular retroversion and compared that to patients without acetabular retroversion.MethodsFifty-one patients (29 male, 22 female) with acetabular retroversion who had undergone FAO between 2007 and 2015 were identified. The minimum 2-year clinical and radiological outcome was compared with 550 patients without dysplasia or retroversion who underwent FAO by the same surgeon. The preoperative and postoperative alpha angle, center-edge angle, Tonnis grade, joint space, and presence of labral tear and chondral lesion were determined.ResultsThe mean age in the retroversion cohort was 27.4 ± 9.5 years compared to 34.5 ± 11.2 years in the control. The mean follow-up was 4.8 ± 1.5 years for retroversion and 4.1 ± 1.2 years for the control. The mean preoperative Short-Form 36 Health Survey and modified Harris hip score were not different between the cohorts. At the latest follow-up, the mean modified Harris hip score and Short-Form 36 Health Survey were significantly lower in the retroversion group (75.4 and 76.5) compared to the control (83.4 and 85.6). There was a higher percentage of failure among retroversion patients (13.7%) compared to the control (2.5%).ConclusionAcetabular retroversion resulting in femoroacetabular impingent may be treated by FAO, but the outcome appears to be less optimal compared to patients with femoroacetabular impingent and no evidence of dysplasia and acetabular retroversion. Hip preservation surgeons should be aware of this anatomic variation and possible inferior treatment results after FAO in these patients.     

The Accuracy of Acetabular Component Position Using a Novel Method to Determine Anteversion

Background

This study compares the differences in acetabular component position, leg length discrepancy, and hip offset between the anterior and posterior approach. A novel method is applied to determine the acetabular anteversion using the C-arm tilt angle for the anterior approach.